A case study integrating numerical simulation and GB-InSAR monitoring to analyze flexural toppling of an anti-dip slope in Fushun open pit

Abstract

Toppling failure of rock slopes is a complicated mode due to a combination of both continuous and discontinuous deformation, especially in dealing with anti-dip rock slopes. In this paper, a novel continuum-based discrete element method (CDEM), which is useful in modeling the entire progressive process from continuous to discontinuous deformation, is proposed to analyze the deformation characteristics, the failure mechanism and the evolution process of a large-scale open pit slope with a typical anti-dip structure. To simulate the slope deformation, the shear strength reduction method (SSR) is adopted to represent the strength degradation of rock mass in the deterioration process. The simulated results are validated using data obtained from a field investigation and continuous monitoring by employing an advanced remote sensing technique called ground-based interferometric synthetic aperture radar (GB-InSAR). To analyze the evolution trend of the anti-dip slope, the subsequent toppling failure mode is predicted using the validated CDEM models. Based on a case study of a slope at the Fushun open pit mine (in Fushun, China), the unique geological structure with various joints and discontinuities, groundwater, intense rainfall, and mining activities are identified as the main triggers for different failure stages. The comparison between the field data and the simulation shows that CDEM accurately depicts the rock deformation and the failure pattern of the studied slope. The proposed numerical modeling techniques can be used for predicting failures of other similar excavated rock slopes. The simulated evolution process and the recorded deformation patterns help engineers to gain a better understanding of rock mass movement of anti-dip slopes, and the presented methodology could be utilized for similar studies and engineering designs.

Stability analysis of underground oil storage caverns by an integrated numerical and microseismic monitoring approach

“…The slope failure mode predicted by CDEM was similar to that obtained by experiments. Li et al (2015) used the CDEM to predict the toppling failure of an opencast mine, and numerical results in micro-crack development were consistent with the GB-InSAR monitoring data. There are more detailed CDEM applications in several aspects of engineering reviewed by Li et al (2008).…”

“…A motivation is to combine advantages of both continuous and discontinuous approaches proposed by Munjiza et al (1995), Li et al (2004), Wang et al (2013), etc. These combined methods include FDEM (FEMDEM) (Munjiza et al, 1995;Munjiza, 2004;Mahabadi et al, 2010Mahabadi et al, , 2012Lisjak et al, 2014Lisjak et al, , 2015 and Continuous-Discontinuous Element Method (CDEM) (Li et al, 2004(Li et al, , 2008Ma et al, 2011;Wang et al, 2013;Li et al, 2015). In the study of Cai et al (2007), the continuum-based software FLAC was coupled with the discontinuum-based software PFC to investigate acoustic emissions in large-scale underground excavations.…”

Subsidence Mechanism and Stability Assessment Methods for Partial Extraction Mines for Sustainable Development of Mining Cities—A Review

“…The detection of precursors of mine-subsidence-induced micro seismicity are of great interest to the research community: Acoustic emission techniques [144][145][146], infrared thermography [151], laser scanning [152] and the SAR (synthetic aperture radar) techniques [153][154][155][156][157][158] have been utilized to study the precursors of rock failure. SAR techniques, in particular, may have the most potential to assess the performance of partial extraction mines, because they can provide accurate, cumulative regional displacements of ground surface.…”

An Optimization of the Analytical Method for Determining the Flexural Toppling Failure Plane

“…Toppling failure, being a kind of typical instability mode for rock slopes, widely exists in domestic and foreign water conservancy, hydropower, highways, and open-pit mine slope engineering. e toppling instability of slopes has caused great harm to people's lives, property safety, and engineering construction [1][2][3][4]. However, due to the cognition limitations of the public with regard to anaclinal layered slopes, these slopes had not been able to arouse people's attention until anaclinal layered toppling landslides frequently occurred.…”